Here's something I brewed a while back to simulate the Lazylord of 4e fame. It's also up on D&D Beyond for those of you who use that service.

The Tactician

Tacticians view the battlefield as a game of chess, using techniques passed through war manuals and following their gut instincts. The knowledge or bravura of a Tactician can be the defining element of a battle that gives the final push towards victory in a small skirmish or a long campaign. Not every fighter learns from every fight, skirmish, or brawl throughout history like the Tactician does.

Master Tactician

At 3rd level, when you take the attack action, you can forego your attack to allow one ally within 30 feet that can see and hear you to make one weapon attack. If you are able to make multiple attacks with the Attack action, this attack replaces one of them. On a hit, they add your Intelligence Modifier to the damage roll.

Battlefield Wit

At 3rd level your knowledge of tactics helps you move quicker through the cacophony of battle. You add your Intelligence modifier to your Initiative rolls.

Student of War

Starting at 7th level, your knowledge of military history is unrivaled. You gain proficiency in History. Your proficiency bonus is doubled for any ability check you make attempting to recall military events.

Inspiring Word

At 10th level, when you use your Second Wind, Action Surge or Indomitable feature you can instead provide the benefits to a friendly creature that can see and hear you within 30 feet.

Castling

At 15th level, you can position a number of friendly creatures equal to your Intelligence modifier (minimum of +1) within 60 feet that can see and hear you, as a bonus action. These creatures can use their reaction to move up to their speed. This movement does not provoke opportunity attacks. Once you use this feature you cannot do so again until you finish a short or long rest.

Fearless Rescue

At 18th level, when an enemy reduces an ally to 0 hit points within 30 feet, you can use your reaction to move up to 5 feet near the enemy that reduced the ally’s hit points and make a weapon attack. Your ally is immediately stabilized and can spend a hit die to regain health, in addition they regain another 1d6 hit points for each opportunity attack you provoked in your movement. Once you use this feature you cannot do so until you finish a long rest.

JNAProductions

2018-05-29, 08:08 PM

Master Tactician, as written, does not use your buddy's reaction. So, Rogues will love this. At level 5, a Champion with a Greatsword hits for two swings at +7 for 12.33 damage apiece, or 24.66 if both attacks hit.

If you have a Rogue buddy, you hit (with the same hit bonus and whatnot) for 12.33+22 (assuming an Int mod of +3), or 34.33 damage if both hit. That's nearly a 40% improvement over a Champion, or any other Archetype not expending resources.

This is either useless (your party is entirely Fighters, or you're the only martial/person who makes weapon attacks, so no one attack is worth more than any other) or, more commonly, ridiculously strong, as shown above. Think about it-Commander's Strike is basically the same thing. But it uses a limited resource.